In a wireless communication system, a terminal may connect to a core network by using a radio access network (RAN). For example, the terminal may connect to a core network device on the core network by using an access network device in the RAN. By using the access network device, the core network device may send signaling to the terminal and receive a corresponding response. However, when the terminal moves out of coverage area of the access network device, the terminal will not receive the signaling of the core network device, and therefore cannot perform proper subsequent processing.